Sunday, 5 May 2013

SEA CUCUMBER FACTS

Sea cucumbers are named after the cucumber fruit whose shape
they resemble. However, they are not
plants but marine animals.

Sea cucumbers belong to the phylum echinoderms, and the class Holothuroidea. They have an elongated body covered in a leathery
skin. An endoskeleton is present just below the skin, which consists of
calcified structures joined to connective gelatinous tissue. They have the ability to squeeze through very
small gaps as their body wall contains collagen, which can be loosened and
tighten at will.

Sea cucumbers have no brain, but have a ring of nervous
tissue surrounding the mouth which sends nerves to the tentacles and pharynx.
In addition there are five major nerves running down the body of the animal.

There are over 1250 species of sea cucumber, most of them in
the Asia pacific region. Sea cucumbers can form dense populations, and make up
90% of animals living on the deep sea floor. Sea cucumbers recycle nutrients in the water by breaking down detritus
and organic matter such as plankton.

Whilst defending themselves, sea cucumbers can release some
of their sticky cuvierian tubules to entangle potential predators. In addition, the may also release a toxic
chemical called holothurin, which is a soapy like substance that can kill any
animal in the vicinity.

If water temperatures increase uncomfortably sea cucumbers
go into a state dormancy called aestivation. They stop eating, slow their
metabolism down and lose weight. Normal functions return when temperatures are
favourable again.

Sea cucumbers are taken from their habitat for human
consumption. They have been harvested
for their healing properties and extracts used oil, cream and cosmetics. Some species are considered a gastronomic delicacy,
especially in Asia. this is leading to a vast decline in sea cucumber population.